Press matrix



United States Patent PRESS MATRIX Paul Ensio Leskinen, Kommunalvagen 20, Huddinge, Sweden Filed Feb. 15, 1967, Ser. No. 616,302 Claims priority, application Sweden, Mar. 4, 1966, 2,893/66 1 Claim. (Cl. 100-295) ABSTRACT or THE DISCLOSURE Press matrix with a press surface consisting of a flat base The present invention relates to press matrices with a press surface consisting of a flat base surface provided with protrusions.

An embodiment of such a matrix, known from British Patent No. 888,636, consists of a solid plate with a flat side surface, constituting the base surface, in which cylindrical pins, which constitute the protrusions, are inserted driven fu-lly down into the bottom holes drilled into the plate to a depth, which in relation to the length of the pins determines the height of the protrusions over the base surface. Obviously, such an arrangement calls for machining of high degree of precision to obtain the proper height of the protrusions, as well as the proper and secure fit for the pins in said bottom holes. In addition, if any other shape of the protrusions than the cylindrical one should be desired, for instance, tooth shape, this method of fastening is hardly practicable without substituting for the pins insertion pieces thus otherwise shaped but also having a cylindrical pin section to fit in the bottom holes, which makes the arrangement still more expensive.

It is an object of the invention to eliminate these disadvantages by designing the matrix so that expensive machining may be avoided by elimination of the necessity of close fitting and by making possible the use of standard elements, which for other purposes are subjected to massproduction at low costs.

According to the invention, the matrix consists of a flat plate of perforated sheet metal stock material one side surface of which, herein referred to as the front-side, constitutes said base surface while the opposite side thereof is referred to as the rear-side, insertion pieces running through the plate through the perforations thereof and projecting over the front-side of the plate where they constitute the protrusions of the press surface, said insertion pieces projecting the rear-side of the plate all to equal height, where they are embedded in a layer of plastic adhering to the insertion pieces and the plate said layer covering the rear-side of the plate to the height of the insertion pieces over that side.

The invention will be further described below with reference to the accompanying drawing in which:

FIG. 1 illustrates a side view of a matrix according to the invention;

FIG. 2 illustrates a fragment of the same matrix as seen from above or below in FIG. 1;

FIGS. 3 and 4 illustrate on a larger scale a detail from 3,400,655 Patented Sept. 10, 1968 FIGS. 1 and 2 in side view and seen from above respectively;

FIGS. 5, 6 and 7 illustrate also on a larger scale a cross section through the matrix according to FIGS. 1 and 2 along the line VIIVII each one in one of succeeding stages of manufacture;

FIGS. 8 and 9 illustrate a modification of a matrix according to FIGS. 1 and 2 respectively; and

FIGS. 10 and 11 illustrate on a larger scale a detail of the same modification in side view as seen from the right or left in FIG. 10 respectively.

All figures are diagrammatic and intended to serve as examples without limiting the scope of the invention. Identical features in the various figures are indicated by identical reference symbols.

In the embodiment according to FIGS. 1 and 2 a plate 2a, perforated with circular apertures 111 (FIG. 5) and the front-side 3 of which constitutes the base surface of the press surface, is provided with cylindrical pins 4a passing through said apertures. The pins fit in the apertures without any special accuracy and by their projections over the base surface form the "protrusions of the base surface. On the rearside 5 of the plate, over which the pins also project, they are embedded in a layer 6 of plastic which adheres to the plate as well as to the pins. This layer covers the plate on this side to the height of the pins over the side in question. By this plastic-bond, which at the same time serves to give the matrix a high degree of stiffness even with a relatively thin sheet metal material the pins will be safely secured in the plate. In addition, a groove 7 in the pins may secure a reinforcement of the adherence to the pins. In this connection it should however be painted out that when the matrix is operated by pressure from the plastic layer side from the press plate of the pressing machine directly or by means of a spacer plate, said pressure will be transmitted directly through the pins Without causing any forces which tend to move the pins in relation to the perforated plate.

The matrix may be built up in a very simple way, for instance, in the following way. The plate 2a is placed above a stop surface 8 at a distance from said surface corresponding to the desired height of the protrusions whereafter the pins 4a are allowed to fall or slide or are lightly pressed down through the holes 1a against the stop surface (FIGS. 3, 5 and 6). Thereafter the plastic layer 6 (FIG. 7) is" applied, which may be effected by any method known within that technique, for instance, by lamination with glass fibre reinforcement or by casting. When the plastic has hardened the matrix is finished.

For this combination of plate and pins it is in most cases possible from available stock material of several types and patterns of perforated plate to select some one that will conform to the desired aperture diameter and aperture distribution pattern, and as pins, some size of available rolls for roller bearings, for instance, may be selected. The pins may otherwise easily be made cheaply by cutting into pieces wire which sufiieiently close will fit in the apertures.

In the same way matrices may be made according to the invention with a multiplicity of other shapes of protrusions than cylindrical pins. FIGS. 8 and 9 illustrate as "an example a matrix in which a plate 2b perforated with rectangular slits 1b is combined with tooth shaped insertion pieces 4b (FIGS. 10 and 11), which may be made by cutting into pieces strip stock material of a size to fit the slits. In many such cases it is also possible to the same effect to use available key elements as insertion pieces.

By the supply of perforated plate of the most different kinds of perforations the possibility of making matrices according to the invention with diverse shapes of protrusions in diverse patterns of distribution is practically without limit. In addition the-protrusions maybe made unequally high in relation to each other by arranging insertion pieces of different height over the base surface in different perforation holes. 7

Moreover, it is possible within the scope of the invention to give the part of the insertion pieces with which they project over the base surface a shape independent of the shape of the remaining portion of the insertion pieces. For instance, the shape of a head of arbitrary kind. Although such a modification will increase the cost of the insertion pieces proper the advantage of using perforated plate for their securing nevertheless remains.

What I claim is:

1. Press matrix With a press surface consisting of a fiat base surface provided with protrusions, comprising in combination a fiat plate of perforated plate stock material 4 one-sideof-whichconstituting the'base surface of the matrix, insertion pieces running through the perforations of said flat plate so as to project over said base surface and constituting said protrusions and also projecting over the opposite side of the plate all to equal height, and a layer of adhering plastic 'material covering said rear side to said equal height there embedding said insertion pieces.

kefer euces Cited UNITED STATES 716,648 12/1902 Stafford 72-464 XR 3,025,727 3/1962 Smith 83-698 XR 2/1967 Bishop 83698 XR BILLY J. WILHITE, Primary Examiner. 

